I suppose they're more like firecrackers or sparklers for children. [Maybe that last bit is a bit pointed, but Urahara shoves candy in his face by the handful when given the opportunity, so he's the last person to point out childish fancy, and that much is clear by the way he leans over.] They mostly just make a lot of noise and flashy lights, but they can startle people too, if you were looking to play a trick on someone.

[Don't suggest to Kylo Ren the alternate uses of firecrackers, Urahara. Just don't.] Loki-san is probably stocking up, now that I think about it...